Bumper with hitch

ABSTRACT

A bumper system includes a tubular bumper beam, and a hitch-supporting bracket. The bracket has an inverted U-shaped section that fits downwardly onto the tubular bumper beam, and further has a laterally-extending planar section with a hole therein that is shaped to support a ball hitch for hauling a trailer. The beam has offset end sections that extend parallel a center section of the beam, but that are offset horizontally. An energy absorber is supported by the beam, and is sufficiently structural to form steps outboard of ends of the beam, and a fascia substantially covers the beam and energy absorber for aesthetics.

BACKGROUND OF THE PRESENT INVENTION

The present invention relates to bumpers having a hitch adapted to haula trailer or the like.

Rear bumpers of vehicles, especially utility vehicles and trucks, areoften adapted with hitches to haul trailers. The hitch-supportingstructure is often incorporated into the bumper in order to reducecomponents and to provide a more compact arrangement. With stampedbumpers, the hitch-supporting structure is simply stamped into thebumper beam as the bumper components are formed and auxiliaryreinforcements are added. However, it is more problematic withrollformed tubular bumper beams, since rollforming operations are nottypically set up to incorporate stamping operations. Further, tubularbeams often use higher-strength materials, such that it is not as easyto form a hitch-supporting structure in a tubular beam. Also,hitch-supporting structures require that the side walls of the materialbe cut and shaped, at a time when it is difficult to support an insideof the tube. This makes it difficult if not impossible to accuratelyshape the wall as desired.

Sometimes, the towing strength of the hitch-supporting structure is morelimited than desired. In particular, class II hitches must be able tosupport a tongue weight of 350 lbs., and must be able to tow a weight of3500 lbs.; while class III hitches must be able to support a tongueweight of 500 lbs., and must be able to tow a weight of 5,000 lbs. Thedifference between the two hitch classes is considerable, and thestructure necessary to pass the tougher class III standard is not easilyachieved without significant cost, weight, and vehicle-built-instructure.

Accordingly, a rear bumper is desired solving the aforementionedproblems and having the aforementioned advantages.

SUMMARY OF THE PRESENT INVENTION

In one aspect of the present invention, a bumper system comprises atubular bumper beam and a hitch-supporting bracket with an invertedsection fit downwardly onto the tubular bumper beam. Thehitch-supporting bracket further has a laterally-extending secondsection with a hole therein, with the second section being shaped tosupport a ball hitch for hauling a trailer.

In another aspect of the present invention, a bumper system for avehicle includes a tubular bumper beam having a center section, endsections, and bent interconnecting sections that interconnect each endsection with an end of the center section. The center section is atleast 25% of a length of the bumper beam and defines a longitudinalprimary centerline. The end sections are at least 15% of the length andeach define a secondary centerline that extends parallel the primarycenterline. An energy absorber includes at least one recess that isshaped to receive a portion of the tubular bumper beam. Mounts adaptedfor attachment to a vehicle are attached to the end sections. Thesecondary centerline is spaced horizontally from the primary centerlinewhen in a vehicle-mounted position.

In another aspect of the present invention, a bumper system for avehicle includes a beam having a face and having mounts adapted formounting to a vehicle frame; and an energy absorber engaging the faceand having end sections located outboard of ends of the beam. The energyabsorber is made of a structural engineering polymeric material and theend sections have flat top surfaces for forming steps outboard of theends of the beam.

In still another aspect of the present invention, a bumper system for avehicle includes a beam having a face and having mounting structuresadapted for mounting to a vehicle frame, and an energy absorber engagingthe face and made of a structural engineering polymeric material. Theenergy absorber includes a honeycomb structure for absorbing energy upona vehicle impact, and further includes accessory-mounting structures formounting and supporting accessories on the energy absorber.

These and other aspects, objects, and features of the present inventionwill be understood and appreciated by those skilled in the art uponstudying the following specification, claims, and appended drawings.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a perspective view of a rear bumper system embodying thepresent invention;

FIG. 2 is an exploded perspective view of FIG. 1;

FIG. 3 is a cross section taken along the line III—III in FIG. 1;

FIG. 4 is an exploded view of FIG. 3;

FIG. 5 is a cross section similar to FIG. 3 but of a modified bumpersystem; and

FIG. 6 is an exploded view of FIG. 5.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

The bumper system 20 (FIGS. 1-2) is designed for use as a rear bumperfor a vehicle, such as for a sport utility vehicle or truck. The bumpersystem 20 includes a beam 21 and an energy absorber 22 with a recess inits vehicle-facing surface for receiving the beam 21. A TPO plasticfascia (not specifically shown) covers the beam 21 and energy absorber22 for aesthetics. The beam 21 may be rollformed or stamped and weldedinto a tubular shape, and/or hydroformed. It can have a rectangular,circular, or other cross section, but it is contemplated that the beamwill be tubular for optimal torsional strength-to-weight ratio. Theillustrated beam 21 is bent to include aligned opposing end sections 100and 101, an offset middle section 102, and transition sections 103 and104 that connect the end sections 100 and 101 to the middle section 102.The end sections 100 and 101 of the beam 21 are aligned and define afirst centerline 103, and the middle section 102 defines a secondcenterline 104 that is spaced horizontally from the first centerline103. In the illustrated beam 21, the first centerline 103 is spacedtoward the vehicle on which the beam 20 is mounted. However, it isspecifically contemplated that the first centerline 103 can be spacedrearwardly away from the vehicle instead, if that would be preferred.Preferably, the bends in transition sections 103 and 104 are made suchthat a full length of the top and bottom walls 105 and 106 is maintainedin parallel horizontal planes, such that they provide good strength in ahorizontal direction parallel an impact force during a vehicle crash.Advantageously, the offset position of the middle section 102 providesfor a step and/or for a towing hitch and ball, as discussed below. Atthe same time, the shape of the beam 21 maintains a strong “foundation”for the bumper system 20. Specifically, the mounts 26 are welded to orfastened to the end sections 100 and 101, and the offset middle section102 is located in the same horizontal plane as the mounts 26 but offsettoward (or away from) the vehicle. Preferably, the end sections 100 and101 are each about 15% to 20% of the beam length, and the center middlesection 102 is about 25% to 30% of the beam length. These lengthsprovide an optimal mounting area on the end sections 100 and 101 andallow end sections 100 and 101 to be accurately positioned in an alignedcondition, while also providing sufficient space on the hitch-side ofthe middle section 101 and also for providing accurate dimensionallocation of the middle section 102. Nonetheless, the dimensions may varydepending on functional and design requirements of the bumper system.

The energy absorber 22 includes an L-shaped middle section 109 defininga step, opposing transition sections 110 and 111 forming sides of thestep, and corner sections 112 and 113 that form corners of the vehicle.A fascia fits over the energy absorber 22 and is supported by the energyabsorber 22. A recess 115 is formed on a vehicle-side of the energyabsorber 22 for mateably receiving the beam 20, and includes a recessportion on a back side of the middle section 109 for receiving themiddle section 102 of the beam 21 along with bracket 126 (see FIG. 3).The energy absorber 22 further includes a recess portion on a backsideof the transition and corner sections 110-113 for receiving respectivetransition and end sections of the beam 21. This creates a supportstructure for transferring loads to the beam 21, both for step supportand for energy absorption from impacts. Notably, it creates a cornerstep structure with a flat top surface located outboard of and beyond alength of the beam 21. (See area B, FIG. 1.) This arrangement providesgood corner impact strength and also provides a step located at an outercorner of the vehicle. The arrangement further provides reduced cost oflow speed rear impacts, by providing a structure that is durable andless prone to dings, scratches, and corrosion than traditional stampedrear step bumpers.

More specifically, the L-shaped middle section 109 (FIGS. 3-4) includesa horizontal leg 117 and an upright leg 118. Apertures are formed in thelegs 117 and 118 to reduce weight and to improve moldability. The cornersection 112 and 113 are mirror images of each other, such that onlycorner section 112 need be described for an understanding by personsskilled in this art. The corner section 112 is not unlike the cornersections described above in regard to energy absorber 22. The cornersection 112 includes an outer “front” wall 120, an interior “rear” wall121, and stiffening walls 122 that extend between the walls 120 and 121to form a honeycomb-like structure optimally suited for energyabsorption and stress distribution during a vehicle crash. Theparticular arrangement of the walls 120-122 can vary depending onfunctional and design requirements. For example, the walls 120-122 canbe varied to provide mounting locations for accessories such astaillights, turn signal lights, license plate illuminating lights, andthe like. This arrangement provides step support in area B (which isoutboard of an end of the metal tubular beam 21). This arrangement alsoprovides an integrated multiple-box-like crush cone at location A oneach end of the energy absorber 22. The crush cones of locations A aregenerally aligned with the vehicle frame rails, and reduce and manageloads into the vehicle frame during a rear impacts. The crush cone ofarea A include perpendicular parallel walls forming square tube sections155-158 (i.e. “boxes within boxes”), each successive tube section beinginterconnected to the next with front or rear walls 159.

The illustrated energy absorber 22 (FIG. 1) is made of a structuralengineering plastic, such as an ABS/PC blend (e.g. Xenoy™ made byGeneral Electric Co) or PC/PBT blends. Because of a strength of thesematerials, the energy absorber 22 can include integrally formedaccessory supporting structures, such as a housing 160 for supporting anelectrical connector 161 adapted for connection to a trailer electricalconnector plug, and/or a fascia-supporting brace 162 adapted forconnection by a fastener to a lower flange of the rear end fascia tosupport the fascia on the vehicle, and/or wire harness retainers. Thematerial of energy absorber 22 also allows other features to beintegrated into the energy absorber 22, such as a license plate supportarea including apertured bosses for receiving screws to secure thelicense plate to the bumper system, light housings for supportinglicense plate illuminating lights, cornering lighting, exterior vehiclelighting, and the like.

The bumper system 20 (FIGS. 3-4) includes a hitch and ball supportarrangement 125 described as follows. A hitch-supporting bracket 126includes a U-shaped section 127 that faces downwardly and engages themiddle section 102 of the beam 21. A first leg 128 extends outwardlyfrom a bottom edge of the outer side flange of the U-shaped section 127at a height about equal to the bottom wall 106 of the beam 21. A secondleg 129 extends downwardly from a bottom edge of the inner side flangeof the U-shaped section 127, and optionally includes a perpendicularhorizontal lip 130 at its lower end. A support bracket 131 includes apair of spaced-apart triangularly shaped side walls 133 welded in placewith welds 134 with a wide end under the bottom wall 106 of the beam 21and that rest on the lip 130. The support bracket 131 also optionallyincludes a horizontal flange 132 that connects sidewalls 133 and thatabuts and supports an underside of the first leg 128 and/or abuts theleg 129 of the bracket 126. The support bracket 131 may also includeholes AA, which are appropriately sized for accepting safety chainhooks, with the support brackets 131 providing sufficient support tomeet safety chain loading requirements.

As illustrated in FIGS. 3-4, a hitch support tube 135 extendshorizontally under leg 128 of the support bracket 126. An outer end ofthe hitch support tube 135 includes a radial face flange 136 forproviding a blunt end on the support tube 135. An inner end 137 of thehitch support tube 135 extends through an aperture 138 on the downwardlyextending second leg 129, with a top of the hitch tube 135 engaging thebottom wall 106 of the beam 21, and with a bottom of the hitch tube 135engaging and resting on the lip 130. An L-shaped retainer 140 is weldedor bolted to the inner end 137 of the hitch support tube 135 and/or aretainer bolt is extended through a hole 141 in the inner end 137 topositively and securely retain the hitch tube 135 to the beam 21 andprevent the hitch support tube 135 from being pulled out of the vehicle.On the outer end, a bolt 142 extends vertically through aligned holes143 and 145 in the first leg 128 and the hitch support tube 135,respectively, and a nut is threaded onto the bolt 142. The aligned holes143-145 can also receive a ball hitch 150 directly in place of the bolt142, if desired, such that the ball hitch is located “on” the step ofthe vehicle. By this arrangement, the ball hitch 150 can be mounteddirectly on the leg 128 and used for class III towing. For example, seeFIGS. 5-6, where the hitch tube 135 is eliminated, and the ball hitch150 is supported on the leg 128.

In the arrangement of FIGS. 3-4, a hitch bar 146 includes an end thatfits matingly into the hitch support tube 135, and a second end thatextends horizontally outward from the vehicle and that drops downwardlya short distance. The hitch bar 146 includes a first hole that alignswith holes 143-145 for receiving the bolt 142 to retain the hitch bar146 to the hitch support tube 135. The hitch bar includes a second hole147 for receiving the threaded stud 148 of a ball hitch 149. Thispositions the ball hitch 149 rearward of the step of the bumper system20 and also slightly lower, which is desirable in many towingsituations.

An important point of novelty of the present arrangement is that a hitchbar (146) is not required. Class III and higher towing is possible offof the step bumper itself, as shown in FIGS. 5-6.

Thus, the disclosed arrangements provide substantial torsional andtensile strength, such that they can be used for Class III towingwithout the use of additional add-on components and brackets. Inparticular, a step bumper arrangement is provided where a hitch tube isnot required. (See FIGS. 5-6.) Specifically, testing has shown that thepresent arrangements are suitable for class III towing, which requiressupport of a tongue weight of 500 lbs, and support of a towing weight of5,000 lbs. Notably, this is a higher class than many previousstep-bumper designs, which were class II and which supported tongueweights limited to 350 lbs. and which supported towing weights limitedto only 3500 lbs.

It is to be understood that variations and modifications can be made onthe aforementioned structure without departing from the concepts of thepresent invention, and further it is to be understood that such conceptsare intended to be covered by the following claims unless these claimsby their language expressly state otherwise.

I claim:
 1. A bumper system comprising: a tubular bumper beam; and ahitch-supporting bracket having an inverted section shaped to fitdownwardly onto the tubular bumper beam, and further having alaterally-extending second section with a hole therein, the secondsection being shaped to support a ball hitch for hauling a trailer. 2.The bumper system defined in claim 1, wherein the inverted section isU-shaped and shaped to straddle the bumper beam.
 3. The bumper systemdefined in claim 2, wherein the second section includes a panel thatextends horizontally when in a vehicle-mounted position.
 4. The bumpersystem defined in claim 3, wherein the inverted section includes a longleg that extends downwardly below a height of the panel, and furtherincluding a hitch support tube that extends perpendicular to the bumperbeam, the hitch support tube extending from the long leg under thebumper beam and supportingly under the panel.
 5. The bumper systemdefined in claim 4, wherein the long leg includes a lip at its lowerfree end, and wherein the hitch support tube includes an end resting onthe lip.
 6. The bumper system defined in claim 4, wherein the end of thehitch support tube extends through an aperture in the long leg, andincluding a retainer that extends through the end on a back side of thelong leg for retaining the hitch support tube to the bracket despitesubstantial towing forces acting on the hitch support tube.
 7. Thebumper system defined in claim 4, wherein the panel and the hitchsupport tube include aligned holes shaped to receive a stem of a ballhitch.
 8. The bumper system defined in claim 4, including a supportbracket positioned under the hitch-supporting bracket and engaging thelong leg and the panel, the support bracket being shaped to support thepanel in a horizontal orientation relative to the hitch-supportingbracket and including holes shaped to provide an attachment point ofsufficient strength to engage and support a safety chain.
 9. The bumpersystem defined in claim 1, including an energy absorber thatsubstantially covers the beam and hitch-supporting bracket, and thatextends outboard of ends of the beam.
 10. The bumper system defined inclaim 1, wherein the bumper beam that includes a center section, endsections, and bent interconnecting sections that interconnect each endsection with an end of the center section, the center section being atleast 25% of a length of the bumper beam and defining a longitudinalprimary centerline, and the end sections being at least 15% of thelength and each defining a secondary centerline that extends parallelthe primary centerline.
 11. The bumper system defined in claim 10,including mounts attached to the end sections of the bumper beam, thesecondary centerline being spaced horizontally from the primarycenterline when in a vehicle-mounted position.
 12. The bumper systemdefined in claim 11, including an energy absorber positioned on a faceof the bumper beam, with at least a portion of the hitch-supportingbracket being located under a center of the energy absorber.